signal-desktop/ts/util/trimPadding.ts
2024-07-11 12:44:09 -07:00

26 lines
672 B
TypeScript

// Copyright 2024 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { Transform } from 'node:stream';
/**
* Truncates the stream to the target size.
*/
export function trimPadding(size: number): Transform {
let total = 0;
return new Transform({
transform(chunk, _encoding, callback) {
const chunkSize = chunk.byteLength;
const sizeLeft = size - total;
if (sizeLeft >= chunkSize) {
total += chunkSize;
callback(null, chunk);
} else if (sizeLeft > 0) {
total += sizeLeft;
callback(null, chunk.subarray(0, sizeLeft));
} else {
callback(null, null);
}
},
});
}